package com.wsj.filter;

import java.io.IOException;

import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.RequestDispatcher;
import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

import com.wsj.web.vo.homeSite.UserBase;

public class AdminCheckFilter implements Filter{
	
	 protected FilterConfig filterConfig = null;
	    protected String loginPath = null;

	    public void destroy() {
	        this.loginPath  = null;
	        this.filterConfig = null;

	    }

	    public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain)throws IOException, ServletException {

	    	HttpServletRequest httpReq =(HttpServletRequest)request;
	    	HttpServletResponse httpResp = (HttpServletResponse)response;
	    	
	    	if(!isAuthenticated(httpReq)){ 		
	    		ServletContext context = filterConfig.getServletContext(  );
	            RequestDispatcher rd = 
	                context.getRequestDispatcher(loginPath);
	            if (rd == null) {
	                httpResp.sendError(
	                    HttpServletResponse.SC_INTERNAL_SERVER_ERROR, 
	                    "Login page doesn't exist");
	            }
	            rd.forward(request, response);
	            return ;
	    	}
	        chain.doFilter(request, response);
	 
	    }
	    
	    /**
	     * Returns true if the session contains the authentication token.
	     */
	    private boolean isAuthenticated(HttpServletRequest request) {
	        boolean isAuthenticated = false;
	        HttpSession session = request.getSession();
	        
	        if (session.getAttribute("UserBase") != null) {
	        	UserBase userBase = (UserBase) session.getAttribute("UserBase");
	        	if(userBase.getUserName()!=null && !userBase.getUserName().trim().equals("")){
	        		isAuthenticated = true;
	        	}
	        }
	        return isAuthenticated;
	    }


	    public void init(FilterConfig filterConfig) throws ServletException {

		    this.filterConfig = filterConfig;
	        this.loginPath  = filterConfig.getInitParameter("loginPath");
	        if(loginPath==null){
	                throw new ServletException("loginPage init param missing");
	        }
	    }

}
